This invention relates to electric motor gear drive systems and the like and to gear lubricant seals for such systems. More particularly, the invention relates to an improved partition plate in a lubricant seal to assist in limiting lubricant loss from an associated gear case and to prevent lubricant migration to the motor shaft bearing and to the environment.
It is known in the art relating to electric motor gear use in drive systems for diesel electric locomotives and the like to provide a railway truck mounted axle hung electric traction motor partially supported upon and geared to a drive axle by engaged pinion and drive gears. The gears are lubricated by heavy fluid lubricant contained in a gear case surrounding the gears on the pinion end of the traction motor and on the axle.
To restrict the escape of lubricant from the gear case along the traction motor shaft, the motor is provided with an outer seal. This combines with a shaft mounted oil slinger to direct lubricant escaping past a labyrinth toward internal drain openings in the outer seal through which the lubricant is returned to the gear case. Lubricant migrating past the partition plate is directed to an external drain in the pinion end bearing cover and is lost from the gear case, preventing contamination of bearing grease, but polluting the environment.
Under certain operating conditions, when the lower part of the drive gear is turning in a direction toward the pinion and the lubricant level in the gear case is relatively high, sufficient lubricant may be pushed or thrown toward the pinion to cause a build-up of lubricant in the vicinity of the internal drain openings. This can force lubricant through the openings into the slinger area and result in a loss of lubricant in the gear case. The effect of this condition, as well as the possibility of excess lubricant flow from the pinion along the traction motor armature shaft and into the slinger area, combine to result in the possibility of excess lubricant loss, requiring inspection and replacement of lubricant at shorter than desired time intervals.
To control the loss of lubricant from escaping the sump through the outer drain applicant has developed an improvement to the partition plate. The improvement returns most of the lubricant that reaches the outer drain and controls or eliminates low sump conditions. The partition can be formed of any material that will maintain its integrity in the range of moderately high to very low temperature operating conditions that may exist in the gear case.
The partition plate is formed to resemble a hook shaped gutter that will catch the lubricant that the partition, when assembled, forms a cavity. When the slinger rotates, the cavity is saturated with lubricant which runs down its faces. As the lubricant runs down partition plate face it is caught in the gutter thus alleviating lubricant to transfer to its outer face and expel to the outer drain.
Lubricant caught in the partition plate gutter is transferred around to its bottom and emptied into the bottom of cavity thus flowing into drain and returned to the sump.
To insure no lubricant will migrate to the back face of partition plate or down the securing bolts bores, a seal between the back mounting faces will be necessary of partition plate and the bearing cover.
The slinger has a flanged diameter with a radius that extends from its face that overhangs the partition plate gutter and allows lubricant remaining on the flange to drip into the gutter and around the radius when rotation has stopped, again transferring lubricant around and into the drain to return to the sump.
Other than drain in outer seal no additional parts are needed other than retaining bolts to secure the seal to bearing cover.
All tolerances between partition plate and slinger should be as close as practical after considering end play and radial run out.
Due to the fact there are no wearing surfaces, performance should continue throughout the life of the motor. If care is taken during disassembly for any reason, partition plate can be reused over and over.
With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.